Surface Temperature of Synthetic Turf
Surface Temperatures
Surface Temperatures High surface temperatures not a new problem 1970 s research traditional, non-infilled Astroturf (Buskirk, et al., 1971; Koon et al., 1971; Kandelin et al., 1976) Surface temperatures up to 50 F higher than natural grass
Children less able to adapt to changes in temperature
High Surface Temperatures How does high surface temperature affect field users? (Astroturf) (Buskirk et al., 1971) Heat sensors in shoes Heat transfer from surface to sole Greater chance of heat related health issues Discomfort, dehydration, heat stroke
When do surfaces get hot? Sunny/Clear Low humidity No clouds Noon 3:00 PM
When do surfaces cool down? Cloud Cover High Humidity/Haze
How hot can synthetic turf get? Highest temperature published in research paper: 200 F (93 C) on 98 F (37 C) day in Provo, UT (Williams and Pulley, 2002) Central PA: 175 F (79 C) (McNitt et al., 2008; McNitt and Petrunak, 2010) (http://ssrc.psu.edu/infill/infill.cfm)
How does this compare to Over 100 F (38 C) - very rare on natural grass Commonly 75 to 95 F (25 to 35 C) on hot day Less than air temperature Generally, synthetic turf 35 to 55 F (20 to 30 C) hotter than natural grass natural grass?
Why do synthetic surfaces get hot? Crumb rubber infill? 1970 s research on Astroturf (Buskirk, et al., 1971; Koon et al., 1971; Kandelin et al., 1976) Traditional Astroturf vs. Infilled synthetic turf McNitt et al., 2008; McNitt and Petrunak, 2010 (http://ssrc.psu.edu/infill/infill.cfm)
Why do synthetic surfaces get hot? Black crumb rubber infill? Black crumb rubber painted white (Devitt, et al., 2007) Very minor surface temperature reduction
What does this tell us? Fibers are a major contributor to high surface temperatures
Why don t natural grass fibers produce heat? Grass leaves transpire Release water vapor Evaporation causes cooling
Attempts to reduce surface temperature
Watering Watering reduces surface temperature for a short period of time Williams and Pulley, 2002 Watering for 30 minutes dropped temperature from 174 F (79 C) to 85 F (29 C) After 5 minutes: 120 F (49 C) After 20 minutes: 164 F (73 C)
Watering McNitt et al., 2008 Temperatures rebounded 20 minutes after watering Temperatures remained 10 degrees cooler than non-watered for 3 hours **Astroturf cooler for longer time (pad close to surface, stayed wet longer)
Attempts to reduce surface temperature Calcined clay Similar to kitty litter Used on baseball infields Traps and holds water McNitt et al., 2008 Infill: 20% calcined clay, 80% crumb rubber No effect on surface temperature
Attempts to reduce surface temperature 1:1 mixture of rubber and larger calcined clay particles
Is Calcined Clay Stable? Calcined clay broke down, lost cooling effect
Attempts to reduce surface temperature Water early morning, then cover with tarp Reduce evaporation prior to use McNitt et al., 2008 No effect on surface temperature
Penn State Heat Studies
Penn State Heat Studies
Infill Materials Surface temperatures of various infill after 1 hour under heat lamp Infill Surface Temperature (F) Black Rubber 156.0 a Tan Rubber Green Rubber Ecofill TPE 153.4 a 147.9 b 141.6 c 136.4 d Temperatures that do not share the same letter are significantly (statistically) different
Fibers Only Surface temperatures of various fibers after 1 hour under heat lamp Fiber Color Surface Temperature (F) Silver 149.4 a Black Green (FieldTurf Duraspine Pro) Gold Green (FieldTurf Revolution) Green (Astroflect) White 144.3 b 140.5 bc 139.8 bc 138.6 c 137.9 c 128.7 d All fibers were FieldTurf Duraspine Pro unless otherwise noted Temperatures that do not share the same letter are significantly (statistically) different
Synthetic Turf Systems Surface temperatures of various fiber-infill combinations after 3 hours under heat lamp. Fiber Color Infill Surface Temperature (F) Gold Black Rubber 171.1 a White Black Rubber 170.4 ab Silver Black Rubber 169.2 ab Black Black Rubber 169.2 ab Green Ecofill 167.3 abc Green (FieldTurf Revolution) Black Rubber 165.6 abcd Green Black Rubber 165.5 abcd All fibers were FieldTurf Duraspine Pro unless otherwise noted Temperatures that do not share the same letter are significantly (statistically) different
Synthetic Turf Systems Surface temperatures of various fiber-infill combinations after 3 hours under heat lamp. Fiber Color Infill Surface Temperature (F) Gold Black Rubber 171.1 a White Black Rubber 170.4 ab Silver Black Rubber 169.2 ab Black Black Rubber 169.2 ab Green Ecofill 167.3 abc Green (FieldTurf Revolution) Black Rubber 165.6 abcd Green Black Rubber 165.5 abcd Green Green Rubber 163.8 bcde Green Tan Rubber 161.1 cde Green TPE 160.5 de Green (AstroFlect) Black Rubber 158.9 e All fibers were FieldTurf Duraspine Pro unless otherwise noted Temperatures that do not share the same letter are significantly (statistically) different
SubAir system
SubAir system
What Can Be Done Now? Practice time mornings and evenings BYU guideline: no use above 120 F (49 C) Athletic trainer involvement Monitor conditions Monitor players Communications with coaches
Future Research Penn State s Center for Sports Surface Research Infill? Fibers?
Penn State s Center for Sports Surface Research Website: http://ssrc.psu.edu Like Penn State s Center for Sports Surface Research @ PSUsportsturf